I trust a manual blood pressure check over the $40K LifePak machines we use @ work.
Same here, I agree, but though I have checked mine manually several times without a hitch, I admit at home I use an automatic one on my wrist. It is a little off from manual, but consistent enough that I would know if I was having a problem or needed a change in BP meds. Can't remember the brand name, but I paid well over $100 for it 4 or 5 years ago when I was recovering from then flesh eating disease and still working well. You can always take yours to your local fire station and have one of the firefighters check it against a manual check for you. Some we have checked have been way off. Manual is always best.
"Onward up many a frightening creek, though your arms may get sore and your sneakers may leak. Oh! The places you'll go!" ~ Dr. Seuss